Naruto System in One Piece - Chapter 499: The End of the Battle

In the year 241 of the 6th era, Constantinople was in turmoil.Emperor Constantine personally lead his army, which was completely annihilated. The pagan empire, riding on the wave of a great victory, annexed the entire eastern territory of the empire, and its military might pointed directly at the capital.The 17-year-old imperial princess Theodora ascended the throne in crisis, facing what was already a terribly damaged realm.Rome was about to fall.....................The wheels of fate spun wildly as a transmigrator appeared on the streets of Constantinople.“According to the original plot, it was only a matter of time before Constantinople would fall.” he pondered.“Perhaps I should first whisk away the empress.”(The book is categorized under game fantasy worlds, set in a magically altered Middle Ages, and another title is 'I Really Can't Lead This Team')

“Do you think sleeping with you once isn't enough after what you did to make me famous? Would you do it a second time?”Li Qingshen remained silent.Ling Momo pouted before biting her finger. “Ten times?” She asked.Li Qingshen still remained silent.Ling Momo tugged at her own hair. She clenched her jaw. “Twenty times?”Li Qingshen turned around to leave.Ling Momo was frantic. She stomped her feet. “Is twenty times still too little? You can't possibly want a hundred times.”Li Qingshen smiled. “That'll do...”

This is a story about Gong Lixin who was the young master of an ancient underground palace in the ancient times. He was raised by his master and forced to partake sexual relationships with numerous people to cultivate his Yin Body. His master who has a Yang Body was going to absorb him after he has reach a level to become stronger. MC refused and killed his master also dying at the same time. Then he transmigrated to the modern time and thinking he will enjoy peaceful life, the end of the world arrived.

Being someone with no special powers except for his martial arts, see how he use his martial arts to dominate the times and find his lovers.

- Description from Novelupdates

After 2000 years has passed, the ruthless demon lord has just been reincarnated! But his aptitude at an academy for nurturing candidates for demon lords is, “Inept”!?